Combined hot water supply system

Abstract

A water heater constituting a combined hot water supply system opens, in starting operation in response to an instruction from a connection controller in STEP 1 , a water-supply servo valve to an operation start opening As corresponding to a water quantity slightly larger than an ignition water quantity Fi in STEP 2 . In STEP 5 , the water heater maintains an opening of the water-supply servo valve at the operation start opening As until a detected temperature Th of a hot-water-supply temperature sensor reaches temperature near a target temperature Ta (Ta−β≦Th≦Ta+α) and limits a water supply quantity from a water supply pipe to be equal to or smaller than a flow rate corresponding to the operation start opening As.

1. A combined hot water supply system in which plural water heaters are connected in parallel to a connection controller and the water heaters are operated in association with one another, wherein
 the connection controller increases the number of water heaters in operation when a predetermined condition for increasing a number of water heaters in operation is satisfied, and 
 each of the water heaters includes: 
 a heat exchanger that heats water supplied from a water supply pipe and taps hot water to a hot water supply pipe; 
 a burner that heats the heat exchanger; 
 a combustion-amount adjusting means for adjusting a combustion amount of the burner; 
 a water-supply-quantity detecting means for detecting a flow rate of the water supplied from the water supply pipe; 
 a water-supply-quantity adjusting means for adjusting the flow rate of the water supplied from the water supply pipe; 
 a hot-water-supply-temperature detecting means for detecting temperature of the hot water tapped to the hot water supply pipe; 
 a hot-water-supply control means for controlling, when a flow rate of water equal to or larger than a predetermined ignition water quantity is detected by the water-supply-quantity detecting means, the combustion amount of the burner with the combustion-amount adjusting means such that hot water of a target temperature is tapped to the hot water supply pipe; and 
 a water-supply controlling means for limiting, when operation is started according to an instruction for increasing the number of water heaters in operation from the connection controller, the flow rate of the water supplied from the water supply pipe to be equal to or smaller than a water quantity at operation start, which is equal to or larger than the ignition water quantity and smaller than a maximum flow rate adjustable by the water-supply-quantity adjusting means, with the water-supply-quantity adjusting means from the start of the operation until a detected temperature of the hot-water-supply-temperature detecting means rises to be within a predetermined temperature range set near the target temperature. 
 
   
   
     2. The combined hot water supply system according to  claim 1 , wherein, when operation of the water heater is started, in the case where a combustion amount of the burner in the another water heater already in operation has decreased, the water-supply controlling means increases, at a first speed that is set lower as a degree of the decrease is larger, a flow rate of the water supplied from the water supply pipe with the water-supply-quantity adjusting means at time when the detected temperature of the hot-water-supply-temperature detecting means rises to be within the predetermined temperature range. 
   
   
     3. The combined hot water supply system according to  claim 2 , wherein, when operation of the water heater is started, in the case where a combustion amount of the burner in the another water heater already in operation has not decreased, the water-supply controlling means increases, at a second speed that is higher than the first speed, a flow rate of the water supplied from the water supply pipe with the water-supply-quantity adjusting means at time when the detected temperature of the hot-water-supply-temperature detecting means rises to be within the predetermined temperature range. 
   
   
     4. A combined hot water supply system in which plural water heaters are connected in parallel to a connection controller and the water heaters are operated in association with one another, wherein
 the connection controller increases the number of water heaters in operation when a predetermined condition for increasing a number of water heaters in operation is satisfied, and 
 each of the water heaters includes: 
 a heat exchanger that heats water supplied from a water supply pipe and taps hot water to a hot water supply pipe; 
 a burner that heats the heat exchanger; 
 combustion-amount adjusting means for adjusting a combustion amount of the burner; 
 water-supply-quantity detecting means for detecting a flow rate of the water supplied from the water supply pipe; 
 water-supply-quantity adjusting means for adjusting the flow rate of the water supplied from the water supply pipe; 
 hot-water-supply-temperature detecting means for detecting temperature of the hot water tapped to the hot water supply pipe; 
 hot-water-supply control means for controlling, when a flow rate of water equal to or larger than a predetermined ignition water quantity is detected by the water-supply-quantity detecting means, the combustion amount of the burner with the combustion-amount adjusting means such that hot water of a target temperature is tapped to the hot water supply pipe; and 
 water-supply controlling means for limiting, when operation is started according to an instruction for increasing the number of water heaters in operation from the connection controller, the flow rate of the water supplied from the water supply pipe to be equal to or smaller than a water quantity at operation start, which is equal to or larger than the ignition water quantity and smaller than a maximum flow rate adjustable by the water-supply-quantity adjusting means, with the water-supply-quantity adjusting means from the start of the operation until a predetermined time elapses. 
 
   
   
     5. The combined hot water supply system according to  claim 4 , wherein, when operation of the water heater is started, in the case where a combustion amount of the burner in the another water heater already in operation has decreased, the water-supply controlling means increases, at a first speed that is set lower as a degree of the decrease is larger, a flow rate of the water supplied from the water supply pipe with the water-supply-quantity adjusting means at time when the predetermined time elapses. 
   
   
     6. The combined hot water supply system according to  claim 5 , wherein, when operation of the water heater is started, in the case where a combustion amount of the burner in the another water heater already in operation has not decreased, the water-supply controlling means increases, at a second speed that is higher than the first speed, a flow rate of the water supplied from the water supply pipe with the water-supply-quantity adjusting means at time when the predetermined time elapses.